/*
 * Copyright (c) 2008, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
package com.github.benmanes.caffeine.openjdk.map;

import static com.google.common.truth.Truth.assertThat;
import static java.util.Locale.US;

import java.time.Duration;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Random;
import java.util.function.Supplier;

import org.testng.annotations.Test;

import com.github.benmanes.caffeine.cache.Caffeine;

/*
 * @test
 * @bug 6612102
 * @summary Test Map implementations for mutual compatibility
 * @key randomness
 */

/**
 * Based on the strange scenario required to reproduce
 * (coll) IdentityHashMap.iterator().remove() might decrement size twice
 *
 * It would be good to add more "Lockstep-style" tests to this file.
 */
@SuppressWarnings({"MultiVariableDeclaration", "NonAtomicVolatileUpdate", "NonAtomicVolatileUpdate",
    "rawtypes", "RedundantStringConversion", "SystemOut", "unchecked", "UnnecessaryFinal", "Var",
    "Varifier"})
public class LockStep {
    void mapsEqual(Map m1, Map m2) {
        equal(m1, m2);
        equal(m2, m1);
        equal(m1.size(), m2.size());
        equal(m1.isEmpty(), m2.isEmpty());
        equal(m1.keySet(), m2.keySet());
        equal(m2.keySet(), m1.keySet());
    }

    void mapsEqual(List<Map> maps) {
        Map first = maps.get(0);
        for (Map map : maps) {
          mapsEqual(first, map);
        }
    }

    void put(List<Map> maps, Object key, Object val) {
        for (Map map : maps) {
          map.put(key, val);
        }
        mapsEqual(maps);
    }

    void removeLastTwo(List<Map> maps) {
        Map first = maps.get(0);
        int size = first.size();
        Iterator fit = first.keySet().iterator();
        for (int j = 0; j < size - 2; j++) {
          fit.next();
        }
        Object x1 = fit.next();
        Object x2 = fit.next();

        for (Map map : maps) {
            Iterator it = map.keySet().iterator();
            while (it.hasNext()) {
                Object x = it.next();
                if (x == x1 || x == x2) {
                  it.remove();
                }
            }
        }
        mapsEqual(maps);
    }

    void remove(Map m, Iterator it) {
        int size = m.size();
        it.remove();
        if (m.size() != size-1) {
          throw new Error(String.format(US, "Incorrect size!%nmap=%s, size=%d%n",
                                        m.toString(), m.size()));
        }
    }

    void test(Supplier<Map> supplier) {
        final int iterations = 100;
        final Random r = new Random();

        for (int i = 0; i < iterations; i++) {
            List<Map> maps = List.of(
                supplier.get()
//                new IdentityHashMap(11),
//                new HashMap(16),
//                new LinkedHashMap(16),
//                new WeakHashMap(16),
//                new Hashtable(16),
//                new TreeMap(),
//                new ConcurrentHashMap(16),
//                new ConcurrentSkipListMap(),
//                Collections.checkedMap(new HashMap(16), Integer.class, Integer.class),
//                Collections.checkedSortedMap(new TreeMap(), Integer.class, Integer.class),
//                Collections.checkedNavigableMap(new TreeMap(), Integer.class, Integer.class),
//                Collections.synchronizedMap(new HashMap(16)),
//                Collections.synchronizedSortedMap(new TreeMap()),
//                Collections.synchronizedNavigableMap(new TreeMap())
                );

            for (int j = 0; j < 10; j++) {
              put(maps, r.nextInt(100), r.nextInt(100));
            }
            removeLastTwo(maps);
        }
    }

    @Test
    public void bounded() {
      test(() -> Caffeine.newBuilder()
          .expireAfterWrite(Duration.ofNanos(Long.MAX_VALUE))
          .maximumSize(Long.MAX_VALUE)
          .build().asMap());
      assertThat(failed).isEqualTo(0);
      assertThat(passed).isGreaterThan(0);
    }

    @Test
    public void unbounded() {
      test(() -> Caffeine.newBuilder().build().asMap());
      assertThat(failed).isEqualTo(0);
      assertThat(passed).isGreaterThan(0);
    }

    //--------------------- Infrastructure ---------------------------
    volatile int passed = 0, failed = 0;
    void pass() {passed++;}
    void fail() {failed++; Thread.dumpStack();}
    void fail(String msg) {System.err.println(msg); fail();}
    void unexpected(Throwable t) {failed++; t.printStackTrace();}
    void check(boolean cond) {if (cond) {
      pass();
    } else {
      fail();
    }}
    void equal(Object x, Object y) {
        if (x == null ? y == null : x.equals(y)) {
          pass();
        } else {
          fail(x + " not equal to " + y);
        }}
//    public static void main(String[] args) throws Throwable {
//        new LockStep().instanceMain(args);}
//    void instanceMain(String[] args) throws Throwable {
//        try {test();} catch (Throwable t) {unexpected(t);}
//        System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
//        if (failed > 0) {
//          throw new AssertionError("Some tests failed");
//        }}
}
